数控机床与原理外文文献翻译中英文.doc

外文文献翻译 () 文献出处：VP Astakhov. Fundamentals Numbercal Control of machine tools[J] International Journal of Machine Tools Manufacture, 2013, 3(1):37-47. 英文原文 Fundamentals Numbercal Control of machine tools VP Astakhov Machine Tools Machine tools are machines for cutting metals. The most important of metal used in industry are lathes, drilling machines and milling machines. Other kinds of metal working machines are not so widely used in machining metals as these three. Drilling is perfurmed with a rotating tool called a drill. Most drilling in metal done with a twist drill. The machine used for drilling is called a drill press. Operations such as reaming and tapping, are also classified as drilling. Reaming consists of removing a small amount of metal from a hole already drilled. Tapping is the process of cutting a thread inside a hole so that a cap screw or bolt may be threaded into it. The lathe is commonly called the father of the entire machine tool family. For turning operations, the lathe used a single-point-cutting tool, which remove metal as it travels past the revolving workpiece. Turning operations are required to make many different cylindrical shapes, such as axes, gear blanks, pulleys, and threaded shafts. Boring operations are performed to enlarge, finish, and accurately locate holes. Miling removes metal with a revolving, multiple cutting edge tools called miling cutter. Miling cutter are made in many styles and sizes. Some have as few as two cutting edges and others have 30 or more. Miling can produce flat or angled surfaces, grooves, slots, gear teeth, and other profile, depending on the shape of the cutters being used. Shaping and planning produce flat surfaces with a single-point-cutting tool. In shaping, the cutting tool on a shaper reciprocates or moves back and forth while the work is fed automatically towards the tool. In planning, the workpiece is attached to a worktable that reciprocates past the cutting tool. The cutting tool is automatically